불교란 시료채취기 (sampler)

영신컨설턴트 (02) 529 8803 ystcha@naver.com 2020 9

 

시추기 수압에 의한 시료 채취기 piston sampler는 수압에 따라 채취시료의 직경 단단함이 결정되어 직경이 크고 단단한 시료는 시료채취가 불가능하다. Rowe cell 수평배수 시험 시 큰 직경의 불교란 시료가 필요하고 시료직경이 크면 시료교란이 적게 된다. 피에조콘 콘 관입기에 의한 시료 채취는 관입력에 따라 시료직경 50, 75, 100mm 채취가 가능하다.

 

국내에서 많은 수압에 의한 piston sampler

 

 

피에조콘 관입기로 원하는 심도까지 관입하고 하단을 로드 속 체인으로 개방하여 시료채취

 

The sampler는 3개의 170 mm liners나 한 개의 510 mm liner가 있다.

Liners 내경 50, 75 ,100 mm

 

구성

1. A piston (item 21) inside the armoured epoxy sample liners (item 26)

inside an outer steel cylinder(item 19).

2. A piston rod friction lock (item 8).

3. A locking part (ball lock, item 11)

4. Extended by a gripping mechanism (claw, item 14)

5. Releasing rod (item 17) and a releasing chain으로 하단 개방

 

The sampling equipment

An outer steel cylinder (item 19) consists of a cutting edge (item 20), two half sleeves (item 25), three armoured epoxy sample liners (item 26)

for St:1 Ø50 and one armoured epoxy sample liner triple for St:1 Ø75 or St: Ø100.

 

And the case may be, a sample retainer and sample retainer sleeve. The cutting edge shall be sharp and not damaged. The sampling is done in the epoxy liners, with the half sleeves in top and bottom.

 

The piston rod (item 18) is a tube with radial holes to let air and water be released upwards. At its tip, the water tight piston head is screwed (item 21).

 

The friction break

The friction break on the piston rod (item 8) is designed to avoid upthrusts of soil and ground water into the cylinder.

 

The break has four jaws held together by a spring ring, six cup springs (item 9) and a tightener for the cup springs (item 10). The jaws are pressed against the piston rod by the tightener and the cup springs. The force on the break can therefore be adjusted with the tightener between some tens of N to approximately 2 kN.

The locking force should be slightly higher than the earth pressure acting against the piston at the depth to sample.

 

The locking system 관입 중 피스톤 로드 고정

The locking system of the sampler (item 11) consists of a piston rod held in place by a ball locking piston. The lock consists of 4 hardened steel balls (item 7) held in a groove in a ball ring (item 5) by the locking piston (item 11). The piston is pressed downwards by a spring (item 12). When the piston is pulled up to its top position, the balls move inwards, there by unlocking the piston system from the sampling cylinders.

 

The gripping mechanism 시료채취심도에서 피스톤 로드 고정 해저

The gripping mechanism is the claw at the top of the sampler (item 14) mounted at the upper end of the spring loaded locking piston (item 11). At the sampling depth, the claw grips the releasing tap (item 15) lowered from the surface with a chain. At the end of the sampling, the claw is opened by the claw opener.

 

The extension tubes CPT로드, 표준관입시험 로드 가능

The extension tubes (item 18) have an outer diameter of 42 mm (SPT rods). Except for the first extension rod, tubes with an OD of less than 50 mm can be used, such as CPT rods of OD 36 mm. The first extension rod comes with the sampler and is an SPT rod in order to let the claw opener move freely along the entire length of the rod. The friction break (item 8), locking (item 11) and gripping (item 14) mechanisms are the same for the Ø50, 75 and 100 mm models.

 

Swedish Geotechnical Society (Report 1:96, 1996): Geotechnical Field Handbook